Burj Khalifa, The Shard, and Rivals by Eva Bogomil
Introduction From the early days, we have invariably been interested in the world we live in, exploring, analysing, and altering it at our will. Humanity has gone a long way from caves to modern skyscrapers, aiming for ever greater heights. The power of human ingenuity has conquered the elements to reach the sky and beyond. Nowadays technologies allow us to build skyscrapers that totally change our idea of a modern world. Throughout the centuries brilliant engineers have been inventing more advanced and complex technologies, expanding our abilities. The Acropolis, St Paul’s Cathedral, the Eiffel Tower and the Sydney Opera House are all marvellous buildings that have remained objects of admiration for historians, architects, and artists, as well as a source of inspiration for many generations. Even to the general public the structures appear breathtaking. The 21st century saw the dawn of super-skyscraper construction. The Shard, Taipei 101, the Princess Tower, the Abraj Al-Bait Towers, and the Shanghai Tower are just some of the outstanding examples the modern world can be proud of. Burj Khalifa, currently the tallest building in the world, crowns this list of our achievements (Figure 1.0) which keep attracting people, making them wonder how such structures could have been built.
Figure 1.0: Height comparison of some of the tallest buildings in the world
This essay will focus mainly on London’s Shard and Dubai’s Burj Khalifa. Both of these skyscrapers are unique in their own way, yet similar. The Shard — currently the tallest building in the United Kingdom — dominates London skyline. One cannot ignore this magnificent building, yet Burj Khalifa, currently the tallest building in the world, interests me the most since its construction was a definitive breakthrough in the history of skyscrapers. The skills and technology had to be taken to a completely new level. The very construction of both skyscrapers challenged the forces of nature.
Overview The Shard. The magnificent shiny 95-storey-high skyscraper became the tallest building in Europe upon its completion on 30 March 2012 at a height of 309.6 metres (1,016 feet). The project was first envisaged in 2000, but it was not until 19 March 2009 that the works had started. The delay was caused by the Chartered Association of Building Engineers (CABE) and English Heritage who believed that the construction of such a skyscraper would ruin the view onto such historic London places as St Paul’s Cathedral and Westminster (Figure 2.1). ‘Tear through historic London like a shard of glass’, said English 1 Heritage, unintentionally giving the skyscraper its current name [12]. That happened despite the Shard’s designer, Renzo Piano, claiming to have been inspired by the spires of London churches and masts of tall ships [4]. Burj Khalifa. The tallest skyscraper in the world with 160 floors and 828 meters high, located in Dubai, UAE was launched on 4 January 2010 (Figure 2.2). The tower is classified as ‘supertall’ (with a height in excess of 1,000 feet) [3]. After 6 years of combined effort of more than 12,000 workers, the tower Figure 2.1: The ‘view’ planning of the Shard has become the icon of the city. The Image: http://www.shardldn.com/construction-history-html/ design of Burj Khalifa was inspired by local nature — the spider lily. The building also set a number of World Records, including the highest occupied floor, the tallest operational elevator, and the tallest aluminium and glass façade, among others [3].
Foundations The Shard towers above Southwark just a couple of streets away from the river Thames. The hole for its foundation was dug down to the clay layer. To construct a firm foundation for the skyscraper and prevent the structure from sinking into the clay, the latter was removed before filling the concrete [2]. The Shard was planned on the site of the former Southwark Towers, and its piles remained in the ground. Since it was impossible to remove them and because the area was surrounded by the London Bridge Station and other facilities, the engineers had to come up with an alternative way to construct the basement [13]. In order to reduce the cost and the timescale, the top-down construction method was used. It enabled the first three storeys and the underground structure to be built simultaneously: the secant pile wall was built together with the steel columns of the bearing piles. The giant hole in the ground level slab gave access to the piles, while the wall kept them from being flooded. A rig attached to the steel plunge columns was then used for supporting the concrete core, while the excavation of the basement floors was taking place underneath. By the time the thin basement slab had been completed, the Shard already had 20 storeys [1][13][14]. This was, indeed, a truly innovative method Figure 2.2: Burj Khalifa (Figure 3.1). Image: https://www.archdaily.com/882100/burj-khalifa-som